Description
Given an array nums, write a function to move all 0's to the end of it while maintaining the relative order of the non-zero elements.
For example, given nums = [0, 1, 0, 3, 12], after calling your function, nums should be [1, 3, 12, 0, 0].
Note:
You must do this in-place without making a copy of the array.
Minimize the total number of operations.
Solution
Two-pointers
class Solution {
public void moveZeroes(int[] nums) {
if (nums == null || nums.length == 0) {
return;
}
int j = 0;
for (int i = 0; i < nums.length; ++i) {
if (nums[i] != 0) {
swap(nums, i, j++);
}
}
}
private void swap(int[] nums, int i, int j) {
if (i == j) {
return;
}
int tmp = nums[i];
nums[i] = nums[j];
nums[j] = tmp;
}
}
